Earlier bioprinting approaches were adapted to form thick tissues. A 3D-printed silicone gasket was used to cast an engineered extracellular matrix as a base layer. “Fugitive ink” was printed in a shape similar to that of renal proximal tubules, and encapsulated with another layer of extracellular matrix.

The in vitro model functions like living kidney tissue, representing a significant advance from traditional 2D cell culture. The result could be an implant or assistive device, and/or more effective clinical trials.